JP2017163085A - Method for manufacturing bonded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a novel bonded body.SOLUTION: The method for manufacturing a bonded body includes: forming a conductor pillar on an electrode of a first substrate; forming an insulating film on a second substrate including a conductive pattern; disposing so that the conductive pattern of the second substrate faces the conductor pillar of the first substrate; and providing an ultrasonic vibration while applying pressure to the first and second substrates, so that the conductor pillar penetrates the insulating film and the conductor pillar is fused to the conductive pattern.SELECTED DRAWING: Figure 1C

Description

  The present invention relates to a method for manufacturing a joined body.

  A joined body in which two electrodes are arranged via an insulating layer containing a resin is, for example, a semiconductor element such as a semiconductor transistor, a capacitive touch panel sensor, a printed board such as a flexible printed board (FPC), or the like. Used in various devices. In such a laminated wiring member, a configuration is generally adopted in which a contact hole is provided in an insulating layer, and both electrodes are connected in the contact hole.

As a method of forming an insulating layer provided with a contact hole, a method of removing a part of the insulating film formed on the entire surface of the substrate by a technique such as a photolithography method or an etching method has been conventionally used. ing.
However, methods other than the method of providing a contact hole in an insulating layer have been sought because of problems with organic solvent resistance and patterning properties.
Patent Document 1 describes a method in which circuit electrodes are bonded together by heat and pressure with an anisotropic conductive film interposed therebetween.

JP 2012-41541 A

Many of the materials used for the substrate and each layer are damaged by heating, and a method for bonding substrates without heating has been demanded.
An object of the present invention is to provide a novel method for producing a joined body.

According to the present invention, the following method for manufacturing a joined body is provided.
1. Conductive pillars are formed on the electrodes of the first substrate, an insulating film is formed on the second substrate including the conductive pattern, and the conductive pillars of the first substrate are formed on the conductive pattern of the second substrate. Arrange to face each other,
A method of manufacturing a joined body in which the conductor pillar penetrates the insulating film and the conductor pillar is fused to the conductive pattern by applying ultrasonic vibration while applying pressure to the first and second substrates. .
2. 2. The method for producing a joined body according to 1, wherein the conductor pillar contains a fluorine-containing compound.
3. 3. The method for producing a joined body according to 1 or 2, wherein the electrode is a transparent electrode.
4). The manufacturing method of the joined body in any one of 1-3 in which the said electrode contains 1 or more selected from the group which consists of indium tin oxide and silver nanowire.
The manufacturing method of a laminated circuit which manufactures a joined body by the method in any one of 5.1-4, and manufactures a laminated circuit using the said joined body.
The manufacturing method of a flexible printed circuit board which manufactures a bonded body by the method in any one of 6.1-4, and manufactures a flexible printed circuit board using the said bonded body.
The manufacturing method of a wiring board which manufactures a bonded body by the method in any one of 7.1-4, and manufactures a wiring board using the said bonded body.
The manufacturing method of a touch panel module which manufactures a bonded body by the method in any one of 8.1-4, and manufactures a touch panel module using the said bonded body.
The manufacturing method of an electronic device which manufactures a joined body by the method in any one of 9.1-4, and manufactures an electronic device using the said joined body.
10. 10. The method for manufacturing an electronic device according to 9, wherein the electronic device is a liquid crystal display, an automobile, a robot, a television, a car navigation, a mobile phone, a game machine, a digital camera, a personal computer, a printer, a light emitting diode illumination, or a wearable device.
11. A method for manufacturing a display device, wherein a joined body is produced by the method according to any one of claims 1 to 4 and a display device is produced using the joined body.
12 12. The method for producing a display device according to 11, wherein the display device is a liquid crystal display device, an electrophoretic display device or an organic EL display device.

  According to the present invention, a novel method for producing a joined body can be provided.

FIG. 1A is a diagram relating to a method of manufacturing a joined body according to an embodiment of the present invention. FIG. 1B is a diagram relating to a method for manufacturing a joined body according to an embodiment of the present invention. FIG. 1C is a diagram relating to a method for manufacturing a joined body according to an embodiment of the present invention. FIG. 1D is a diagram relating to a method for manufacturing a joined body according to an embodiment of the present invention. FIG. 2A is an explanatory diagram for explaining the application position of the conductor composition ink. FIG. 2B is an explanatory diagram illustrating the application position of the conductor composition ink. FIG. 3A is an explanatory diagram of a longitudinal cross-sectional shape of the conductor pillar in the method according to the embodiment of the present invention. Drawing 3B is an explanatory view about the longitudinal section shape of the conductor pillar in the method concerning one embodiment of the present invention. FIG. 3C is an explanatory diagram of a longitudinal cross-sectional shape of the conductor pillar in the method according to the embodiment of the present invention. FIG. 4 is a diagram showing conductor pillars and electrodes.

In the method for manufacturing a joined body according to the present invention, the conductor pillar is formed on the electrode of the first substrate, the insulating film is formed on the second substrate including the conductive pattern, and the conductive pattern of the second substrate is formed. The conductor pillars of the first substrate are arranged so as to face each other, and ultrasonic vibration is applied to the first and second substrates while applying pressure, so that the conductor pillars break through the insulating film, and the conductor pillars are conductive. Fuse to the pattern.
As a result, the substrate is not damaged by heat, and an electrically connected joined body can be formed.

1A to 1D are views showing a method for manufacturing a joined body according to an embodiment of the present invention.
As shown in FIG. 1A, a conductor pillar 5 is formed on the electrode 3 of the first substrate 1.
As shown in FIG. 1B, an insulating film 6 is formed on the second substrate 2 including the conductor pattern 4.
As shown in FIG. 1C, the conductive pattern 4 of the second substrate 2 is disposed so that the conductor pillars 5 of the first substrate 1 face each other, and pressure is applied to the first substrate 1 and the second substrate 2. By applying ultrasonic vibration while applying, a joined body 10 as shown in FIG. 1E can be formed.

The first substrate and the second substrate may be the same or different. Examples of the first and second substrates include a rigid base material such as a glass substrate, a silicon wafer, and a ceramic substrate, and a flexible base material such as a film made of a plastic resin. Can be mentioned.
Examples of the plastic resin include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyimide (PI), polyetheretherketone (PEEK), polycarbonate (PC), polyphenylene sulfide ( PPS) and polyetherimide (PEI).

  The first and second substrates may be a single layer or a laminate. Examples of the layer to be formed include an insulating film such as an oxide film and a nitride film, a semiconductor film, a conductive film, a planarization layer containing a curable resin, a barrier layer, and the like. These may be used alone or in combination of two or more.

  When the substrate has transparency, the transmittance in the visible light region is preferably 80% or more. Here, the transmittance can be measured by JIS K7361-1 (a test method for the total light transmittance of a plastic-transparent material).

The first substrate includes an electrode. The electrode should just be formed on the board | substrate. The electrodes are usually formed in a pattern on the substrate. Examples of the pattern include a line shape and a pad shape used for an electrode pad.
The conductor pillar is formed at a desired position on the electrode, but the electrode may have a portion where the conductor pillar is not formed.

  The material of the electrode is not particularly limited as long as it has desired conductivity. For example, Ta, Ti, Al, Zr, Cr, Nb, Hf, Mo, Au, Ag, Pt, Cu, Mo—Ta Metals such as alloys, Ag alloys, Cu alloys, Al alloys, conductive inorganic materials such as indium tin oxide (ITO) and indium zinc oxide (IZO), polyethylene dioxythiophene / polystyrene sulfonic acid (PEDOT / PSS), A conductive organic material can be used. The electrode may be a transparent electrode.

In addition, the electrode may include a conductive material such as a metal material, carbon nanotube, and graphene. Thereby, printing of an electrode is attained.
Examples of the metal material include metal microparticles, metal nanoparticles, metal nanowires, and combinations thereof. Metal nanoparticles and metal nanowires are preferred.
Examples of the metal of the metal material include silver, copper, mercury, tin, indium, nickel, palladium, platinum, and gold. Moreover, these alloys may be sufficient. Gold, silver, copper and alloys thereof are preferred, and silver, copper and alloys thereof are particularly preferred. These may be used alone or in combination of two or more.

The metal nanoparticles preferably have an average diameter of 100 nm or less, more preferably 3 to 50 nm, and even more preferably 5 to 45 nm.
The metal nanowires preferably have an average diameter of 50 nm or less, more preferably 3 to 30 nm, and even more preferably 5 to 28 nm. Moreover, 100 micrometers or less are preferable, as for the average length of metal nanowire, 5-50 micrometers is more preferable, and 8-30 micrometers is more preferable.

  A carbon nanotube is a carbon-based fiber material having a shape in which a graphite-like carbon atomic surface (graphene sheet) having a thickness of several atomic layers is wound into a cylindrical shape. Single-walled nanotubes (SWNT), multi-walled nanotubes (MWNT), etc. Can be mentioned. Single-walled carbon nanotubes include a chiral type, a zigzag type, and an armchair type because of the difference in the structure of the graphene sheet. These may be used alone or in combination of two or more.

The carbon nanotubes are preferably single-walled nanotubes having a large aspect ratio, that is, thin and long. For example, an aspect ratio of 10 ² or more, and preferably 10 ³ or more carbon nanotubes.
The average length of the carbon nanotubes is usually 1 μm or more, preferably 5 μm or more, more preferably 10 μm or more, and the upper limit of the average length is not particularly limited, but is, for example, about 10 mm. As the outer diameter, extremely minute carbon nanotubes on the order of nm are known. The carbon nanotubes are preferably surface-treated with an organic compound. Specifically, it is preferable to improve dispersibility using a surfactant.

  About the above diameter, length, major axis, thickness, etc., for example, using a transmission electron microscope, measure the diameter, length, major axis, thickness, etc. of 100 or more conductive materials, It can be obtained on average. In particular, in the case of the particle diameter, for example, the projected area circle equivalent diameter of the particles can be measured, and the average can be calculated.

  A conductive material may be used individually by 1 type, and may combine 2 or more types.

The thickness of the electrode is not particularly limited as long as it has desired conductivity, but is preferably 30 nm to 50 μm, more preferably 50 nm to 40 μm, and particularly preferably 100 nm to 40 μm.
When it is within the above range, the electrode can be formed satisfactorily and good conductivity is easily exhibited.

  The thickness means a thickness obtained by a general measurement method. As a method for measuring the thickness, for example, a stylus type method of calculating the thickness by tracing the surface with a stylus to detect unevenness, observation with a transmission electron microscope (TEM), a scanning electron microscope (SEM), etc. Examples thereof include a method for measuring an image, an optical method for calculating a thickness based on a spectral reflection spectrum, and the like. In addition, you may use the average value of the thickness measurement result in the several location of the structure used as object.

The wettability of the electrode surface is not particularly limited as long as a desired conductor pillar can be formed. As the wettability of the electrode surface, for example, the contact angle between the electrode surface and water is preferably 30 ° to 95 °, more preferably 40 ° to 90 °, more preferably 40 ° at 25 ° C. The angle of 80 ° or less is particularly preferable.
When it is within the above range, it becomes easy to form a good conductor pillar without conduction failure.

  The contact angle can be measured, for example, by dropping 1 microliter of liquid onto the measurement target, observing the shape of the dropped liquid droplet from the side, and measuring the angle formed by the droplet and the measurement target. . The contact angle can be measured, for example, using a contact angle measuring device manufactured by Imoto Seisakusho, contact angle meter DM-901 (manufactured by Kyowa Interface Science).

The electrode formation method can be the same as a general electrode formation method. Specifically, it can be performed on the substrate by a vacuum deposition method, a sputtering method, a PVD method such as an ion plating method, a CVD method, or the like. After being formed on the entire surface, it may be etched into a predetermined pattern using a photolithographic method, or may be formed by fixing a metal mask having openings in a predetermined pattern.
Alternatively, a printing method using a conductive paste containing the above metal material, carbon nanotube, graphene, or the like may be used. Examples of the printing method include an inkjet method, a dispenser method, a screen printing method, a gravure offset printing method, and a reverse offset printing method. For the conductive paste, for example, a solvent used in a conductor composition ink described later, an arbitrary component, and the like may be appropriately selected and used.

The conductor pillar preferably includes a conductive material. Examples of the conductive material include the same conductive materials as those mentioned for the electrode. 1 type may be used individually and 2 or more types may be combined.
A plurality of conductor pillars may be formed.

  The conductor pillar further preferably contains a liquid repellent, and preferably has liquid repellency. Thereby, it becomes easy to function favorably as a via post.

  Examples of the liquid repellent include fluorine-containing compounds such as fluorine-containing thiol compounds and fluorine-containing disulfide compounds. Fluorine-containing thiol compounds are preferred because they form both self-assembled monolayers and, particularly when metal particles are used as the conductive material, both conductivity and liquid repellency can be achieved.

  Examples of the fluorine-containing thiol compound include a fluorine-containing thiol compound having an aromatic ring and an alkanethiol having a fluorinated moiety. Among these, at least one compound selected from the group consisting of a fluorine-containing thiol having 6 to 20 carbon atoms having an aromatic ring (preferably a benzene ring) is preferable from the surface modification property of the metal particles.

Specific examples of the fluorine-containing thiol having 6 to 20 carbon atoms having an aromatic ring include trifluoromethylbenzenethiol (for example, 4-trifluoromethylbenzenethiol and 3-trifluoromethylbenzenethiol), pentafluorobenzenethiol. 2,3,5,6-tetrafluorobenzenethiol, 2,3,5,6-tetrafluoro-4- (trifluoromethyl) benzenethiol, 2,3,5,6-tetrafluoro-4-mercaptobenzoic acid Examples include acid methyl ester, 3,5-bistrifluoromethylbenzenethiol, 4-fluorobenzenethiol and 11- (2,3,4,5,6-pentafluorobenzyloxy) -1-undecanethiol. Among these, trifluoromethylbenzenethiol and 2,3,5,6-tetrafluoro-4- (trifluoromethyl) benzenethiol are particularly preferable from the viewpoint of liquid repellency.

Examples of the fluorine-containing disulfide compound include a fluorine-containing disulfide compound having an aromatic ring and a disulfide compound having a carbon chain having a fluorinated portion.
Specific examples of the fluorine-containing disulfide compound having an aromatic ring include compounds obtained by dimerizing the above-mentioned fluorine-containing thiol compound. From the viewpoint of liquid repellency, trifluoromethylbenzenethiol or 2, 3, 5, A compound obtained by dimerizing 6-tetrafluoro-4- (trifluoromethyl) benzenethiol is particularly preferable.

The content of the conductive material is preferably 25% by mass or more and 99% by mass or less, and more preferably 30% by mass or more and 99% by mass or less with respect to the total amount of the conductor pillars.
The content of the liquid repellent is preferably 2% by mass or less, and more preferably 1.8% by mass or less, based on the total amount of the conductor pillars.
By being in the said range, it becomes easy to make electroconductivity and liquid repellency compatible.

Further, the conductor pillar may include a polymerizable monomer and a polymer thereof.
Examples of the polymerizable monomer include ester monomers and acrylate monomers.
Examples of the ester monomers include phenoxypolyethylene glycol (preferably diethylene glycol) acrylate, nonanediol acrylate, and the like.
Examples of the acrylate monomer include phenoxyethyl acrylate and tetrahydrofurfuryl acrylate.
One type may be used alone, or two or more types may be used in combination.

  When the polymerizable monomer and the polymer thereof are included, the content is preferably 10% by mass or less, and more preferably 8% by mass or less, based on the total amount of the conductor pillars.

  The conductor pillar may contain an optional component such as a dispersant and a solvent of a conductor composition ink described later.

For example, 90% by mass or more, 95% by mass or more, 98% by mass or more, 99% by mass or more, and 100% by mass of the conductor pillar may be made of a conductive material.
The conductor pillar is, for example, 90% by mass or more, 95% by mass or more, 98% by mass or more, 99% by mass or more, and 100% by mass of the conductive material and the liquid repellent, or the conductive material, the liquid repellent, and the polymerizable. It may consist of a monomer and a polymer of a polymerizable monomer.

The surface energy of the conductor pillar is preferably more than 20 mN / m and not more than 80 mN / m. It is more preferably 23 mN / m or more and 50 mN / m or less, further preferably 23 mN / m or more and 40 mN / m or less, and particularly preferably 23 mN / m or more and 38 mN / m or less.
When the density is 20 mN / m or less, the amount of the liquid repellent increases, and the conductive material in the conductor composition ink may aggregate to keep the ink state. If it exceeds 80 mN / m, the liquid repellency is lowered and the insulating film may not be opened.

From the viewpoint of surface energy and conductivity, the conductive material, or the conductive material and the liquid repellent are preferably exposed on the surface of the conductor pillar.
Examples of means for adjusting the surface energy include adjusting the type and blending amount of the liquid repellent.

  The surface energy is analyzed by the geometric mean method based on the extended Fowkes equation of Kitazaki and Hata, for example, from the contact angle value measured with each solvent (Natsuaki Kitasaki, Toshio Hata et al., Journal of Japan Adhesion Association, Vol. 8 ( 3) 131-141 (1972)).

  The liquid repellency of the conductor pillar is not particularly limited as long as the conductor pillar can play the insulating film and function as a via post when the conductor pillar enters the insulating film. The contact angle between the surface of the conductor pillar and water is preferably 80 ° or more, and more preferably 90 ° or more and 120 ° or less. If it is less than 80 °, it may be difficult to maintain the conductor pillars.

“The conductor pillar has liquid repellency” means that the contact angle between the surface of the conductor pillar and water is larger than the contact angle between the surface of the insulating film on the second substrate and water.
Specifically, the difference between the contact angle between the surface of the conductor pillar and water and the contact angle between the surface of the insulating film and water is preferably 5 ° or more, and more preferably 20 ° or more. If the difference between the contact angles is less than 5 °, it may be difficult for the conductor pillar to repel the insulating film.
Further, the upper limit value of the contact angle difference is appropriately determined according to the material of the conductor pillar, the material of the insulating film, and the like, and is not particularly limited, but is 100 °, for example.

The conductor pillar is formed, for example, by applying a conductor composition ink on the electrode. The conductor composition ink is preferably applied in a pattern.
“Applying the conductor composition ink in a pattern” means that the conductor composition ink is applied on the electrode so as to have a predetermined plan view shape. The conductor composition is applied to the entire surface of the electrode on which the electrode is formed. This does not include the case where physical ink is applied.

The conductor composition ink preferably contains a conductive material and a solvent. The conductor ink preferably further contains a liquid repellent. The conductor composition ink may further contain a polymerizable monomer.
Examples of the conductive material, the liquid repellent, and the polymerizable monomer include the same materials as the conductive material, the liquid repellent, and the polymerizable monomer mentioned for the conductor pillar.

  In the conductor composition ink, the conductive material may be a nanocolloid dispersed in a solvent.

The solvent is not particularly limited as long as it can disperse or dissolve the conductive material and the liquid repellent.
Solvents include water, alcohol solvents (monoalcohol solvents, diol solvents, polyhydric alcohol solvents, etc.), hydrocarbon solvents, ketone solvents, ester solvents, ether solvents, glyme solvents, halogen solvents. A solvent etc. are mentioned. These solvents may be used alone or in a combination of two or more.
Among these, alcohol solvents are preferable from the viewpoint of printability. Examples of alcohol solvents include isopropyl alcohol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, cyclohexanol, 1-methoxy-2-propanol, ethylene glycol , Glycerin and 1,3-propanediol.

  Examples of the ketone solvent include cyclohexanone and methyl isobutyl ketone.

The surface tension of the solvent is preferably 20 mN / m or more and 65 mN / m or less at 25 ° C. When the surface tension of the solvent is within the above range, the conductor composition ink can be sufficiently adhered to the ground.
The surface tension can be measured by a pendant drop method.

  Examples of the alcohol solvent having a surface tension of 20 mN / m or more and 65 mN / m or less at 25 ° C. include ethylene glycol, glycerin, and 1,3-propanediol. Among these, 1,3-propanediol is particularly preferable.

  The content of the conductive material is preferably 15% by mass or more and 80% by mass or less, and more preferably 20% by mass or more and 70% by mass or less with respect to the total amount of the conductor composition ink. If it is in the said range, a conductor pillar can be formed more efficiently.

When the liquid repellent is included, the content of the liquid repellent is preferably 10% by mass or less, and more preferably 5% by mass or less with respect to the total amount of the conductor composition ink. If it is in the said range, an electroconductive material can be disperse | distributed favorably.
When the liquid repellent is included, the content of the liquid repellent is preferably 0.1% by mass or more from the viewpoint of the liquid repellency of the conductor pillar.

When the polymerizable monomer is included, the content of the polymerizable monomer is preferably 10% by mass or less, and more preferably 5% by mass or less with respect to the total amount of the conductor composition ink.
Moreover, when a polymerizable monomer is included, as for content of a polymerizable monomer, 0.1 mass% or more is preferable.

  20 mass% or more and 85 mass% or less are preferable with respect to the conductor composition ink whole quantity, and, as for content of a solvent, 40 mass% or more and 80 mass% or less are more preferable. When the content of the solvent is within the above range, the conductor composition ink can be appropriately applied.

For example, 90% by mass or more, 95% by mass or more, 98% by mass or more, 99% by mass or more, and 100% by mass of the conductor composition ink may be made of a conductive material and a solvent.
The conductive composition ink is, for example, 90% by mass or more, 95% by mass or more, 98% by mass or more, 99% by mass or more, and 100% by mass of a conductive material, a liquid repellent and a solvent, or a conductive material, You may consist of a liquid agent, a polymerizable monomer, and a solvent.

The conductor composition ink may contain an optional component such as a dispersant.
The optional component is preferably 10% by mass or less based on the total amount of the conductor composition ink.

  The method for applying the conductor composition ink is not particularly limited, and examples thereof include an inkjet method, a dispenser method, a screen printing method, a gravure printing method, a gravure offset printing method, a reverse offset printing method, and a relief printing method. Among these, it is preferable to use an inkjet method, a dispenser method, or a screen printing method.

The conductor composition ink may be baked after being applied.
The firing method is not particularly limited as long as the solvent contained in the applied conductor composition ink can be removed and electrical connection can be made, and a general firing method can be used. Specifically, firing can be performed using a hot plate, light firing, or the like.

  The firing temperature and firing time are appropriately adjusted according to the type of solvent, liquid repellent, etc. contained in the conductor composition ink.

Although it does not specifically limit as a calcination temperature, 100 to 220 degreeC is preferable and 110 to 180 degreeC is more preferable.
When it exceeds 220 ° C., the conductive material may be deteriorated and it may be difficult to exhibit desired conductivity. Moreover, when the temperature is lower than 100 ° C., the residual amount of the solvent in the conductor pillar is increased, and there is a possibility that impurities are mixed into the insulating film at the time of bonding.

  The firing time is not particularly limited as long as the solvent contained in the conductor composition ink can be removed to form a conductor, but is preferably 1 minute to 60 minutes, and preferably 3 minutes to 30 minutes. The following is more preferable, and 5 minutes or more and 20 minutes or less is particularly preferable.

  If it is less than 1 minute, the residual amount of the solvent in the conductor pillar increases, and it may be difficult to exhibit desired conductivity. If it exceeds 60 minutes, the liquid repellent may deteriorate and it may be difficult to exhibit desired liquid repellency. In addition, productivity may be reduced.

2A and 2B are explanatory diagrams for explaining the application position of the conductor composition ink.
As shown in FIG. 2A, the conductor composition ink may be applied only on the electrode to form the deposit 5A. The conductor composition ink is applied on and near the electrode as shown in FIG. The kimono 5A may be formed. In this case, the conductor composition ink is usually applied on the electrode so as not to be electrically connected to the other electrode 3a adjacent to the electrode.
It is preferable to adjust the wettability of the electrode surface and the physical properties of the conductor composition ink to facilitate the adjustment of the shape of the conductor pillar, and to apply the conductor composition ink only on the electrode.

  The shape of the conductor pillar in plan view is not particularly limited as long as it can function as a via post, and examples thereof include a circular shape, an elliptical shape, a rectangular shape, and a polygonal shape. Among these, the planar shape of the conductor pillar is preferably a circular shape or an elliptical shape.

3A to 3C are explanatory views of the longitudinal cross-sectional shape of the conductor pillar in the method according to the embodiment of the present invention.
The longitudinal cross-sectional shape of the conductor pillar means the cross-sectional shape of the conductor pillar in the direction perpendicular to the substrate.
Examples of the vertical cross-sectional shape of the conductor pillar 3 include a semicircular shape as shown in FIG. 3A, a semi-elliptical shape as shown in FIG. 3B, a trapezoidal shape, a quadrangular shape, and the like (not shown). Moreover, these shapes may have a flat part or a hollow in the center. In FIG. 3C, a shape having a flat portion at the center of the semi-elliptical shape is shown.

The size of the conductor pillar is not particularly limited as long as a via post capable of conducting an electrode and a conductive pattern through the conductor pillar can be formed. For example, the size is preferably 1 μm or more and 5000 μm or less, and preferably 5 μm or more and 1000 μm or less. Is more preferable, and 10 μm or more and 100 μm or less is particularly preferable.
If the thickness exceeds 5000 μm, it may be difficult to achieve high definition and high integration of the manufactured joined body. On the other hand, when the thickness is less than 1 μm, it may be difficult to make the conductor pillar and the conductive pattern conductive.
“The size of the conductor pillar” refers to the size of the shape of the conductor pillar in a plan view. For example, when the shape in a plan view is a circle, the diameter refers to the diameter. Say. Further, when the shape in plan view is a shape having a short side and a long side, such as a rectangle or an ellipse, the width of the short side is meant. Moreover, when the planar view shape is a polygonal shape, it refers to the diameter of the inscribed circle.
Specifically, the size of the conductor pillar means a distance indicated by u in FIG. FIG. 4 is a diagram showing the conductor pillar 5 and the electrode 3.

The height of the conductor pillar is not particularly limited as long as it can be electrically connected to the conductive pattern, but is preferably 100 nm or more and 100 μm or less, and more preferably 1 μm or more and 60 μm or less.
When it exceeds 100 μm, it may be difficult to improve the flatness of the conductive pattern side surface of the manufactured joined body. If it is less than 100 nm, it may be difficult for the conductor pillar to exhibit desired conductivity.
The “height of the conductor pillar” refers to the value of the portion where the distance in the vertical direction to the base material is maximum in the longitudinal cross-sectional shape of the conductor pillar.

The aspect ratio (height / size) of the conductor pillar is not particularly limited as long as a via post can be formed, but is preferably 0.001 or more and 1 or less, and preferably 0.01 or more and 0.8 or less. More preferably, it is 0.03 or more and 0.8 or less.
If it exceeds 1, it may be difficult to form the conductor pillar itself, and the conductor pillar may be easily damaged. If it is less than 0.001, it may be difficult for the conductor pillar to exhibit sufficient conductivity and liquid repellency.

  After the formation of the conductor pillar, the conductor pillar may be subjected to a hydrophilic treatment. The hydrophilization treatment is not particularly limited as long as the decrease in the conductivity of the conductor pillar can be suppressed and the contact angle between the surface of the conductor pillar and water can be reduced. For example, hydrophilization treatment using hydrogen plasma can be used.

  Examples of the conductive pattern material, physical properties, formation method, and the like are the same as those of the above-described electrode.

The thickness of the conductive pattern is not particularly limited as long as conduction between the conductor pillar and the electrode can be obtained. Specifically, 30 nm to 50 μm is preferable, 50 nm to 40 μm is more preferable, and 200 nm to 20 μm is particularly preferable.
It can be measured in the same manner as the electrode thickness described above.

The insulating film may be an adhesive body of the resin composition, and may be formed by pasting on the conductive pattern, or may be formed by applying the resin composition and curing such as thermosetting or photocuring.
The insulating film may be a single layer or a plurality of films.
The pressure-sensitive adhesive body of the resin composition is preferably a double-sided tape without a commercially available support film or a commercially available adhesive. Examples of the adhesive of the resin composition include acrylic adhesives, silicone adhesives, rubber adhesives, and the like.

Examples of the material for the insulating film include organic materials such as acrylic resin, phenol resin, fluorine resin, epoxy resin, cardo resin, vinyl resin, imide resin, and novolac resin. These may be used alone or in combination of two or more.
The insulating film is preferably an acrylic adhesive, an epoxy resin, an imide resin, or the like.

The thickness of the insulating film can be appropriately selected according to the use of the joined body, but is preferably 90 nm or more and 90 μm or less, and more preferably 900 nm or more and 54 μm or less.
If it exceeds 90 μm, it may be difficult to make the conductor pillar function as a via post. If it is less than 90 nm, it may be difficult to exhibit sufficient protection.

  The thickness of the insulating film is preferably 60 to 100%, more preferably 70 to 95% of the height of the above-described conductor pillar.

  The resin composition preferably contains a resin. You may contain other components, such as a polymerization initiator, as needed. Examples of the resin include polymers. Monomers and oligomers may be used. It may be used alone or in combination of two or more.

  Examples of the resin include thermosetting resins such as ionizing radiation curable resins such as acrylate resins, epoxy resins, and polyester resins, acrylate resins, urethane resins, epoxy resins, polysiloxane resins, and fluorine resins. Examples thereof include resins. Among these, a thermosetting resin is preferable because the insulating property can be further improved.

  The ionizing radiation is used for photocuring and means electromagnetic waves or charged particles having energy that can be cured by polymerizing molecules. For example, all ultraviolet rays (UV-A, UV-B, UV-C), visible light, gamma rays, X-rays, electron beams and the like can be mentioned.

  Fluorine-based resins include fluorine-added polyimide, fluorine-added polyparaxylene, polystyrene, Cytop (registered trademark), Teflon (registered trademark), Teflon (registered trademark) AF, fluoropolyaryl ether, The top (made by Asahi Glass Co., Ltd.) etc. are mentioned.

The resin composition may contain a solvent.
The solvent contained in the resin composition can be appropriately selected according to the liquid repellency of the conductor pillar, the wettability of the base on which the insulating film is formed, the viscosity, and the like, and is used for a general resin composition. It can be similar to that.

  In addition, when the resin is a fluorine-based resin, it is usually preferable to use a fluorine-based solvent.

  The resin composition further contains a polymerization initiator, a photosensitizer, an antioxidant, a polymerization inhibitor, a crosslinking agent, an infrared absorber, an antistatic agent, a viscosity modifier, an adhesion improver, etc., if necessary. You can also

The viscosity of the resin composition is not particularly limited as long as it has a predetermined coatability.
The specific viscosity of the resin composition is preferably 1.0 mPa · s or more and 50000 mPa · s or less at 25 ° C., more preferably 5 mPa · s or more and 40000 mPa · s or less, particularly preferably 20 mPa · s or more and 30000 mPa · s or less. preferable.
If it is less than 1.0 mPa · s, it may be difficult to form a coating film of the resin composition. When it exceeds 50000 mPa · s, it may be difficult to obtain the effect of the difference in surface wettability.

  The method for measuring the viscosity is not particularly limited as long as the viscosity can be accurately measured, but examples include a method using a viscosity measuring device such as a rheometer, a B-type viscometer, a capillary viscometer, and the like. It is done. Moreover, as a measuring method of a viscosity, you may use a digital viscometer (Toki Sangyo Co., Ltd. TV-35).

The surface tension of the resin composition is not particularly limited as long as it has a predetermined coating property.
The specific surface tension of the resin composition is preferably 5 mN / m or more and 70 mN / m or less at 25 ° C., more preferably 10 mN / m or more and 50 mN / m or less.
If it is less than 5 mN / m, it tends to be difficult to play the conductor pillar at the time of joining, and if it exceeds 70 mN / m, it may be difficult to form an insulating film.

The method for measuring the surface tension is not particularly limited as long as the surface tension can be accurately measured. For example, the Wilhelmy method (plate method), the hanging drop method (pendant drop method), and Young-Laplace. Method, du Nouy method and the like.
Further, for example, a high-precision surface tension meter (Kyowa Interface Science DY-700) can be used for measuring the surface tension.

The application method is not particularly limited as long as an insulating film having a desired thickness can be formed, and a general application method can be used.
Specific examples include a slit coating method, a spin coating method, a screen printing method, a die coating method, a roll coating method, a bar coating method, an LB method, a dip coating method, a spray coating method, a blade coating method, and a casting method. .
Especially, since the flatness of an insulating film can be made favorable, the screen printing method and the slit coat method are preferable.

It arrange | positions so that the conductor pillar of a 1st board | substrate may oppose the conductive pattern of a 2nd board | substrate through an insulating film. It is preferable that the conductor pillar of the first substrate is in contact with the insulating film, and the first substrate and the second substrate are fixed via the insulating film.
In the fixing, when the insulating film is not an adhesive, it is preferable to cure by a curing method suitable for the insulating film to be used after the contact between the conductor pillar of the first substrate and the insulating film. For example, if it is a thermosetting resin, it is heated, and if it is a photocurable resin, it is irradiated with ionizing radiation.

  When the conductor pillar is projected onto the conductive pattern in the vertical direction from the first substrate, it is preferable that 100% of the projection of the conductor pillar is in the conductive pattern. 90% or 80% of the projection of the conductor pillars may be in the conductive pattern.

  After the above arrangement, ultrasonic vibration is applied to the first and second substrates while applying pressure. The ultrasonic vibration is preferably applied to a portion where the conductor pillar and the insulating film are in contact with each other and fixed.

The pressure is preferably from 0.01 to 0.7 MPa, more preferably from 0.1 to 0.6 MPa.
The ultrasonic vibration may be applied to both the first substrate and the second substrate, or may be applied to only one of the first substrate and the second substrate. The ultrasonic vibration is preferably 20 to 50 kHz, and more preferably 20 to 40 kHz.
The application time of the ultrasonic wave is preferably 0.5 to 30 seconds, and more preferably 1 to 15 seconds.

By applying ultrasonic vibration to the first and second substrates while applying pressure, the conductor pillar can break through (penetrate) the insulating film, and the conductor pillar can be fused to the conductive pattern.
It is preferable that the conductor pillar breaks while opening the insulating film.
In the fusion of the conductor pillar and the conductive pattern, it is preferable that the tip of the conductor pillar is melted and fused to the conductive pattern.
Thereby, an insulating film having a via post can be formed by a simpler method as compared with a conventional method using a photolithography method or the like.

The joined body produced by the method of the present invention can be applied to a device having a laminated structure in which two electrodes are conducted through a via post, and can be used for a laminated circuit, a flexible printed board, a wiring board, a touch panel module, and the like.
Further, the present invention can be applied to semiconductor elements, touch panel sensors, RF-ID (Radio Frequency Identification), organic electroluminescence (EL) devices, and the like. The semiconductor element can also be used for a temperature sensor, a pressure sensor, or the like.
In addition, electronic devices such as liquid crystal displays, automobiles, robots, televisions, car navigation systems, mobile phones, game machines, digital cameras, personal computers, printers, light-emitting diode (LED) lighting, wearable devices, liquid crystal display devices, electrophoretic display devices It can be used for display devices such as organic EL display devices.

Production Example 1
Silver nanocolloid (average particle size: 40 nm), ester monomer NK ester AMP-20GY (manufactured by Shin-Nakamura Chemical Co., Ltd.), 2,3,5,6-tetrafluoro-4- (trifluoromethyl) benzenethiol and Solvent (mixed solvent of water, ethylene glycol, 1,3-propanediol, and glycerin in a mass ratio of 1: 1: 1: 1) is in a mass ratio of 46.7: 3.0: 0.8: 49.5. Were mixed to prepare a conductor composition ink.

Production Example 2
Silver nanowires (manufactured by Aldrich) having an average diameter of 25 nm and an average length of 10 μm were dispersed in isopropyl alcohol so that the solid content concentration was 0.5% by mass to produce a silver nanowire dispersion.

Example 1
Two glass substrates (Corning Eagle XG, size: 40 mm × 40 mm, thickness: 0.7 mm) were prepared.
A metal mask having openings in a predetermined pattern was fixed on the surface of the first glass substrate, and an ITO thin film (thickness 150 nm) was formed by sputtering to form an electrode.
The conductor composition ink obtained in Production Example 1 was printed on a desired portion of the ITO pattern by a screen printing method and baked at 160 ° C. for 15 minutes to form a conductor pillar having a height of 52 μm.

A metal mask having openings in a predetermined pattern was fixed on the surface of the second glass substrate, and a copper thin film (300 nm) was formed by vacuum deposition to form a conductive pattern.
Further, a base material-less double-sided tape GA5905 (manufactured by Nitto Denko Corporation, thickness 50 μm) made of an acrylic pressure-sensitive adhesive was affixed on the conductive pattern to a portion to be fixed to the first glass substrate.

The conductor pillar on the first glass substrate and the second glass substrate so that the conductor pillar on the first glass substrate faces the conductive pattern on the second glass substrate via an acrylic adhesive. The upper polyimide layer was brought into contact and fixed.
Ultrasonic small metal bonding machine G436D (manufactured by Seidensha Electronics Co., Ltd.)
Placed in.
Under the following conditions, the substrate was pressurized while applying ultrasonic vibration to the fixed part to obtain a joined body.

Ultrasonic vibration frequency: 28.50 kHz
Ultrasonic wave application time: 10s
Pressure: 0.5Mpa

  When conduction of the obtained joined body was confirmed, it was confirmed that conduction was achieved.

Example 2
Instead of forming a copper thin film by vacuum deposition, the silver nanowire dispersion obtained in Production Example 2 was applied with a dispenser and dried to form a conductive pattern (thickness 50 nm), and the ultrasonic wave application time was 3 s. In addition, a joined body was produced and evaluated in the same manner as in Example 1 except that the pressure was changed to 0.15 MPa. As a result, it was confirmed that it was conducted.

Comparative Example 1
A joined body was produced and evaluated in the same manner as in Example 1 except that ultrasonic vibration was not performed. As a result, continuity was not obtained, and the conductor pillar on the first substrate and the conductive pattern on the second substrate could not be joined.

  The joined body produced by the method of the present invention can be used for laminated circuits, flexible printed boards, wiring boards, touch panel modules, and the like.

DESCRIPTION OF SYMBOLS 1 1st board | substrate 2 2nd board | substrate 3 Electrode 3a Other adjacent electrode 4 Conductor pattern 5 Conductor pillar 5A Deposit | attachment 6 Insulating film 10 Assembly

Claims (12)

Conductive pillars are formed on the electrodes of the first substrate, an insulating film is formed on the second substrate including the conductive pattern, and the conductive pillars of the first substrate are formed on the conductive pattern of the second substrate. Arrange to face each other,
A method of manufacturing a joined body in which the conductor pillar penetrates the insulating film and the conductor pillar is fused to the conductive pattern by applying ultrasonic vibration while applying pressure to the first and second substrates. .   The method for producing a joined body according to claim 1, wherein the conductor pillar contains a fluorine-containing compound.   The method for producing a joined body according to claim 1, wherein the electrode is a transparent electrode.   The manufacturing method of the joined body in any one of Claims 1-3 in which the said electrode contains 1 or more selected from the group which consists of indium tin oxide and silver nanowire.   The manufacturing method of a laminated circuit which manufactures a joined body by the method in any one of Claims 1-4, and manufactures a laminated circuit using the said joined body.   The manufacturing method of a flexible printed circuit board which manufactures a joined body by the method in any one of Claims 1-4, and manufactures a flexible printed circuit board using the said joined body.   The manufacturing method of a wiring board which manufactures a bonded body by the method in any one of Claims 1-4, and manufactures a wiring board using the said bonded body.   The manufacturing method of a touch panel module which manufactures a bonded body by the method in any one of Claims 1-4, and manufactures a touch panel module using the said bonded body.   The manufacturing method of an electronic device which manufactures a conjugate | zygote by the method in any one of Claims 1-4, and manufactures an electronic device using the said conjugate | zygote.   The method of manufacturing an electronic device according to claim 9, wherein the electronic device is a liquid crystal display, an automobile, a robot, a television, a car navigation, a mobile phone, a game machine, a digital camera, a personal computer, a printer, a light emitting diode illumination, or a wearable device. .   The manufacturing method of a display apparatus which manufactures a bonded body by the method in any one of Claims 1-4, and manufactures a display apparatus using the said bonded body. The method for manufacturing a display device according to claim 11, wherein the display device is a liquid crystal display device, an electrophoretic display device, or an organic EL display device.

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